In highway surfacing or resurfacing operations, any surface depression or irregularity, such as cracks and joints and the like, must be prepared for surfacing by cleaning and filling with some type of filler material. Until relatively recently, this was done with the same type of material as the surfacing material and was typically done in the same operation. However, filling irregularities in this manner often resulted in weaknesses in the finished surface at such points, and repair to the surface was often necessary within a short period of time.
In recent years, it has been found that the necessity for such repairs may be reduced by the overlayment of an impregnated fiber mat between the filled irregularities and the surfacing material. The application of such a mat, however, is at best a multiple stage operation and its use has been somewhat limited because of the problems and expenses involved. In such an operation, the area to be filled must first be opened and cleaned of debris, as is done in the filling method previously described. Then the area is filled with a conventional filler material such as hot asphalt, up to the level of the surrounding area. The surface of the filled area is then treated to promote bonding and a fiber mat which has been previously impregnated, or which is impregnated with an asphalt material as it is applied over the filled irregularity, is put down. The top surface of the impregnated fiber mat is then treated to bond to the surfacing material, and finally, the surfacing material is applied.
Aside from the expense of such a multi-stage operation, the procedure described is additionally disadvantageous in that after the application of the fiber mat, the surface cannot be traveled on until the top surface material is applied, and such application must be done within a short period of time. This often involves the coordination of the efforts of different contractors, and typically involves substantial delays.